During the 2023 Brazilian Carnival holiday weekend, record-breaking rainfall—reaching 682 mm (26.9 in) in 24 hours—caused deadly floods and landslides across the state of São Paulo.

[2] On 18–19 February 2023, an area of low pressure off the coast of Brazil brought moist onshore flow, leading to significant rainfall in the region.

[6] Wind exceeding 55 km/h (34 mph; 30 kn) and waves of more than 1 m (3.3 ft) prompted the closure of the Port of Santos on 18 February.

[8] By 21 February, 7.5 tons of relief goods including food, water and hygiene kits were distributed in São Paulo.

[2] Some aid efforts were hampered due to criminal activities like looting trucks carrying donations.

[2][6] On 22 February, the NAM Atlântico set sail from the Rio de Janeiro Navy Arsenal with a field hospital on board, with a capacity that could be increased to up to 300 beds.

[2][13] The vessel arrived at the port of São Sebastião on 23 February, also carrying 28 medics of several specialties including surgeons, dentists and orthopedists, as well as 180 marines who were designated to operate heavy machinery in aid of the search and rescue efforts.